The present invention relates to strip cutter apparatus for rolled sheet formed of rubber and rubber-like or elastomeric material.
In the rubber industry the so-called rolled sheet or hide is a basic product in the manufacturing process. The rolled sheets -- as the name suggests -- are produced by rolling a rubber mixture consisting of raw rubber, fillers and different chemicals. The agglomerates composed of the raw mixture, delivered from the internal mixer to the rolling mill, are worked into a finer state by revolving upon the front roll of this double roll-rolling mill. Such mixture is then removed from this roll as a sheet in heated condition at a temperature between 90.degree. C. and 140.degree. C. and having an average thickness of 8 to 10 mm and an average width of 600 to 800 mm (in larger manufacturing installations, such as tire production plants, up to 1400 mm width) and conducted by means of a conveyor belt into the cooling machine, the so-called batch-off-installation. In the batch-off-installation this sheet or hide is quenched with cooling water at the starting region in the so-called spray chamber and upon passing through the tunnel the residual cooling and drying is accomplished by ventilators. At the end of this manufacturing process the sheet is either cut into plates or deposited upon pallets or the like in a zig-zag configuration and delivered, for instance, in stacks between 50 and 1000 kg to the mixture storage. There is added a parting compound or release agent to the spray water, in order to prevent bonding of the sheet during stacking upon the pallet.
These rolled sheets serve as the starting product for all further manufacturing operations in the rubber factory, whether such be, for instance, the production of tires, the fabrication of profiled sections, hoses, molded parts, shoe soles or other rubber products.
However, the rolled sheets cannot be used for production in the form in which such arrive as an intermediate product from the mixer, typically in the form of rolled sheets of 8 to 10 mm thickness and usually 600 to 800 mm width and in lengths up to 50 meters. The rolled sheets thus must be cut into so-called blanks, and for the most part the sheets are cut into strips between 40 and 120 mm width. By means of these cut strips it is now possible to directly charge the extruder of injection molding machines or extruders for producing profiled sections, hoses, plates and so forth.
Oftentimes, these strips are cut from the cold rolled sheets during a separate working step with the aid of so-called strip cutting machines. Owing to the toughness of the rolled sheet in its cold condition there is required the application of considerable forces and, furthermore, the danger exists that the strips cut from the rolled sheets will again stick together in an uncontrolled manner at the cut locations, because at these locations the rolled sheet is not covered with any release agent or parting compound. Hence, it is oftentimes necessary to apply powder to the cut strips, resulting in contamination of both the raw mixture as well as the room in which the work is carried out.
Another heretofore known possibility of manufacturing strips from rolled sheets resides in delivering such once more to the rolling mill and then withdrawing from the rolling mill, or for instance by means of a three roll-calender, strips of the desired width in a heated condition. The cooling of the individual strips is accomplished in a water basin (throughpass basin or spray basin). Also in this case the water is imbued with a release agent. All of these operations are time-consuming additional operations, which also require an appropriate amount of space, need an additional energy supply and also can impair the quality of the unvulcanized rubber mixture.